One design goal for integrated circuits is to reduce power consumption. Devices with batteries such as cell phones and laptops particularly need a reduction in power consumption in the integrated circuit to extend the life of the battery. Additionally, a reduction in power consumption prevents overheating and lowers the heat dissipation of the integrated circuit, which in some cases eliminates or simplifies heat sinks and/or fans required to cool the integrated circuit. As well, the reduction in power consumption of the integrated circuit reduces the AC power draw for the device containing the integrated circuit.
A competing design goal for integrated circuits is increased performance. One way to increase performance is by increasing a maximum operating frequency of a circuit. In order to increase the maximum operating frequency of a circuit, or to integrate more functionality in a smaller area, integrated circuit manufacturing technology shrinks the device size of individual components (e.g. transistors) on the integrated circuit.
However, as component device size scales from 250 nanometers to 130 nanometers or below, a current draw of a device in standby mode referred to as static leakage becomes an increasingly large part of the power budget of the integrated circuit. For example, simulations show that; for an integrated circuit dissipating 50 watts constructed using 130 nanometer devices, greater than 20 percent of the power dissipated is due to static leakage. For even smaller devices, simulations show that the static leakage of an integrated circuit using 50 nanometer feature sizes comprises about 50 percent of the total power budget.
One solution for reducing static leakage includes use of one or more sleep transistors coupled to a logic gate of the integrated circuit. Application of a control signal to the sleep transistor may reduce the static leakage of the logic gate.